A hard-disk drive (HDD) is a non-volatile storage device that is housed in a protective enclosure and stores digitally encoded data on one or more circular disks having magnetic surfaces (a disk may also be referred to as a platter). When an HDD is in operation, each magnetic-recording disk is rapidly rotated by a spindle system. Data is read from and written to a magnetic-recording disk using a read/write head which is positioned over a specific location of a disk by an actuator.
A read/write head uses a magnetic field to read data from and write data to the surface of a magnetic-recording disk. As a magnetic dipole field decreases rapidly with distance from a magnetic pole, the distance between a read/write head, which is housed in a slider, and the surface of a magnetic-recording disk must be tightly controlled. An actuator relies in part on a suspension's force on the slider and on the aerodynamic characteristics of the slider air bearing surface (ABS) to provide the proper distance between the read/write head and the surface of the magnetic-recording disk (the “flying height”) while the magnetic-recording disk rotates. A slider therefore is said to “fly” over the surface of the magnetic-recording disk.
An HDD includes at least one head gimbal assembly (HGA) that includes a read/write head, a lead suspension attached to the head, and a load beam attached to the slider, which includes the head at a distal end of the slider. The slider is attached at the distal end of the load beam to a gimbal portion of the load beam. Typically, the slider is electrically interconnected to the lead suspension via connection pads on the respective components, which are solder ball bonded (SBB) together to form the final electrical interconnection between the components.
One SBB method places a solder ball between the connection pad of the slider and the connection pad of the suspension, reflows the solder ball by using laser light, and electrically interconnects the connection pad of the slider and the connection pad of the suspension. To prevent oxidation of the solder surface, the solder ball is reflowed in an inert gas environment such as nitrogen. The device for feeding and ejecting the solder ball by a compressed gas, such as nitrogen gas, is typically referred to as a solder ball jet (SB-jet).
The solder ball must be accurately placed between the pads in order to reflow the solder ball with the laser light. However, the head slider is an extremely small component, and its size continues to decrease with successive designs. Therefore, the connection pads and the solder balls placed at the pads are also becoming smaller, and placing the solder balls at the exact positions becomes more challenging. In addition, the solder ball often rotates during reflow. Thus, the placements of the solder balls frequently require correction, which becomes a source of degradation in the efficiency of the manufacturing process.
FIG. 3 is a diagram illustrating a solder ball jet of a prior art solder ball bonding tool. In the SB jet 300 illustrated in FIG. 3, pressure is applied to a solder ball by a compressed gas as the solder ball is falling to a nozzle 302 or after the solder ball is held at the tip of the nozzle 302, and laser light from laser 308 irradiates the solder ball through the path of laser optical path 304 to eject melted solder. When the solder ball supply into nozzle 302 is through the inclined solder ball feed path 306, supplying the solder ball takes time and, consequently, the takt time becomes long.